Which of Newton's laws best explains why motorists should buckle qe6 r3f:njs+u .eg0 gu/6ytpq l.kgf0-up?

  When you sit on a chair, the resultant force on you /mkm(tl,;wd vis

  In the absence of an external force, a mocp7 d:7,lj1du dwr l7nving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turnedb i se(o92h/hs off, while traveling in empty space, ths/sb92ho ( ehie starship will

  A rocket moves through empty space in a straight l,d kn)+c7fe- 0m(tk8ltbtmk kine with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the mkk0)(ec tft k ,k- 78nb+mltdforce that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving m ;-xf kt.h o44qdgt3kbus, facing forward, and you suddenly fall forward. You can i3; ft.mxodh4 q-g4kktmply from this that the bus's

  You are standing in a moving bus, facing forward, anmhhff3l:n km uo39xh-nx ;;79 c63:vmzvnhg qd you suddenly fall forward as the b qkcngfu3fn 963znh;9:hlv: 7hommmx -;x3vh us comes to an immediate stop. What force caused you to fall forward?

  A constant net force actgx-5m brd6ishc; 6h:ts on an object. Describe the motion of the object.

  The acceleration of an object is inversely pr( 2s: (cimqkyfoportional to

  A net force F accelerates a mass m with an acceleration a7sala,x:lra :f d 07wm. If the same net force is applied to mass 2ma7ld mrw7x las0:,a:f , then the acceleration will be

  A net force F acts on a mass m and o6./xwrgs8t yproduces an acceleration a. What acceleration results if a net force 2F acts on masstw /ogxr y6.8s 4m?

  If you blow up a balloon, and then rele*-bt tpt z1:jbase it, the balloon will fly away. This isztpjttb1b* :- an illustration of

  Two cars collide head-on. At every (;srr( fzx i. fjao 6l1xfvw.,moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on laf(rf, 1 x.f z (rivw;.joxs6the first. This is an example of

  If you exert a force F on an object, the force wxxwqb4;xal r*8)*s o qhich the object exerts on you wi )wo*rx4a*qsx; lx 8qbll

  Action-reaction forc;n,cefr44 +uih8b+ cng7zc xe*4fnm5o q/zud es

  Action-reaction forces arefk4rbduhn/hh.9 8 wt .sa,g8e

  A 20-ton truck collides with a 1500-lb car av y-gyj97wr//bc:l cwqd1; ownd causes a lot of damage to the car. Since a lot of damage is done on tgd/cc9-1q7wr y;jy o/ v:l wbwhe car

  An object of mass m sits on a flat table. The Earth pulls on th* gw,ez *bud-zckx8 *nis object with force mg, which we will cxd**w8c n*- ,zuz bgekall the action force. What is the reaction force?

  A child's toy is suspended1zfc(s duvx g**s yxdv*/70td: nqx 7w from the ceiling by means of a string. The Earth pulls downward on the toy with its weight for1stvwzdx*y*:c n0 x*dvxqsdu(g7f / 7ce of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched p, pbwx w+ 5qsnh1+v1fto you with a 1500-N instantaneous force. The ball hits the bat with f, v+11 x+qpbswp5w hnan instantaneous force, whose magnitude is

State Newton's three laws2ipis4d:h6zup x(u: .gv- nu p.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth-c+ki glz k;k;m5w+1gx7 u wqd. Which of the following is trz i qgkwm+w7c-+l g;dk;5u xk1ue about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acty*l**ywn fh0 os at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N 9 *42xoxnxjmlor a person weighingx2 4jm*on9x xl 600 N?

  A stone is thrown straight up. At the top of its path, the net force acting : z2gy drxpp4xm tbq89c(wu9:on it igu(8z49txyb :rqx c: wd92ppms

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heightbhyb3gmr76yt b4o7 r -. Ignore air re-h 67ry7y4mr bbo gb3tsistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respecti6;nuxk)b fx;k ve terminal velocities. Which objectx kfnxub;6k) ; experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevaton0q *6gke3hb ir. The elevator is moving up at constant speed. What is the teb6e3 khgin0q *nsion in the string?

  An object of mass m is hanging by a string from the ceiling of an elevpqd ;e,)itx.v9vuetu/e( a+ j ator. The elevator is moving upwarx;e qudv i(u/+t a.ve),et9pj d, but slowing down. What is the tension in the string?

  The force that keeps you from slidinib-t eb fz7misz(b.y. n+ 9ds2g on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to keepmx sc:w0-zoh/i /c1 j.)radpx pushing it wit/ jxcx )s/pid-z1cwa0:.h r omh constant velocity, because

  A horizontal force axng -,sx(:.isks f 0qbccelerates a box from rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force is doubled. What happens to thex 0s:xg fn,q(sk. b-si box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thuq;fjjq 7-2hx ls we can ded -;j2fjqlq7h xuce that

  A block of mass M slides down a 59 9 f) dbgxotwaxi(-.9 myvfifrictionless plane inclined at an angle q with the horizontai 9t.vwmb-99gdaxof5y )ix(fl. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an a, pd k 5l5j;pzql 71sb5ndr0pvngle q with the horizontal. The normal reab 75ldrjqp sdk5v1 ;0pz ,n5plction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless pl .re4 -.8*w6fkpsma z 7xkdlcaane inclined at an angle q with the horizontal. The *.6wezlk47 cd 8aaxpf .k-msrgravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released sim tk+6svffp /2 :qvsq6vvw5i6fjz f:u 9ultaneously on an inclined plane :iqu5f 6t f+svvzk/26fp9 sqv 6v:jwfthat makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-, pb4snh ;-dtgN force is applied to the object, and it acceld-;g 4np hsb,terates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in pihvtg-l:33)ny; el g7.0 s. What is the average forwg:gill)p t-;3v3hne yard force on the car?

  Starting from rest, a 4.0-kg body reaches a speed ofdg c*30qx ko)qc7 hcf0 8.0 m/s in 2.0 s. What is the net fgocf30 7cqqc*0kx d) horce acting on the body?

  An antitank weapon fires a 3.01fj0bgm- 9 dgh5b pov80-kg rocket which acquires a speed of 50.0 m/s after travelipvo h50g b f89mgd-1jbng
90.0 cm down a launching tube. Assuming the rocket was accelerated uniformly, what is the average force acted on it?

  If you push a 4.0-kg mass with the same forp *vlqnd2e)+9 2tw9z(y v wzcrce that you push a 10-kg mass from rest2z pn29()t zc*v+elvd 9 qrwyw,

  What is the mass of a pe n;zeb)gwuqv,8 kk*.hxo 4 xn;lk;s)lrson who weighs 110 lb?

  What is the mass of an object that wez 2c kvnf9j 4oih+h8n1kw.m-qighs 250 N on the surface of the Earth where the accelerk4vnomf cz1+-hi .wjq 82hnk9ation due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. Whac c *-3,sllgfgkqj p),7yaz::+ qv 6kr4q aurut is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that onc* u3,a ,y6gkuf+ac) :jl:plzs 4qqvkq -7 grr the Earth?

  Object A weighs 40 N on Earthq: 3o/c9iqmll, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth o9i qqm :ll3c/of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pr9ghih3 huc5+x5g +n rulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates towardr9gx5+h5ncr+u3h ihg Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surfaghxqtky1.a ;qxl4dy oblqse e- 9;938ce. A force F acts on the stack, and it accelerates -.x;8;q 949edlhbk3ty gq1oxlsq aey at $3.0 \; m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0 \; m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a scale in an elevator. h yc:/+;njcyg zvk9(w What will the scale be reading wy+;cjzg cyw9kv (n:h/hen the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is0i+5w wn,h6xp;wkxsi 60.0 kg and the elevator accelnx xwiw;+wkh5 , i0ps6erates downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If the mass of the pe + 6gpack) 3njrz9p t21rglj*h6dz.oxrson is 60.0 kg and the elevatorrn6og2.lj)c 1jg6 +pzt 9dx*azhp3rk accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One force has a magnitxer l7dc1l,u g9;oc2 kude of 8.0 N and is directe2lk ,cxo9ge7cul; d r1d due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg 31+0 yxhc;ikugy3s barests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force x31+ cy;0bgu3 sykhia of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the i3zlkyr:9 tqy5*n h* iflatbed of a truck. It is held in place by metal brackets that c*: *q5i9yry3tnhz k ilan exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kul 2go;t4zz4bpjcg-; g and m = 0.40 kg, what is the magnitude of the acceleration of the syste2 -g4l;ucb ;z4pjzo tgm? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in boicp8+;ua+ vvee6+qbfb-- g o9h+oga f1,qn Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore frictiq-1hbg op 89+avfu-;iva+o, nebo q6+b+fgc eon and the mass of the pulley.)

  A student pulls a box of books on a smootk;: +2/+k 1r6rhxsozgexxop (a( ojxges 5nb+h horizontal floor with a force of 100 N in a direction5jgx+orxh2x gp se sna/o ++xzko(;:k 6er(b1 of $37^{\circ}$ above the horizontal. If the mass of the box and the books is 40.0 kg, what is the acceleration of the box?

  A student pulls a box of books on a smooth horizontal floor with a force of r n 1zqrkq7lj -iu00d:1xcv,ehx hw *rn.(x3p 100 N in a directiondqhh,031 x i xnq7-j.e0x(pcvu1: r*nrrlzwk of 37.0e above the horizontal. If the mass of the box and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two jjcte-4 6; fg)sn:u0x+ khsynq8*me tropes as shown in Fig. 4-2. What are the tensionc0x u*k:e th nn ;j)s 4fj+y-tq8sgme6s in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the tra(4b giby*c zp7ff(byc p*7z gb4iic light?

  Two boxes of masses m and 2m are in contact with each other on a fo1a ,zg3 594:o9gbe ymcsjzq drictionless surjm 3 z9e:gy ogd9q1ac o4szb,5face. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on lzvhz jp8h+4) a frictionless surface. (See Fig. 4-3.) What is the net force on tv+lh hz84 zpj)he more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the f kmol.azq rf 0gys;ae8a 0it,y4a(( /horward force on the more massive box is F, what is the tension in the connectin4(.qaokiaeza;syh( 0 a/rtl0m fg y,8 g rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the;bd(b(meq m+ojhf; 9,v(mv cq forward force on the more massive box is F, what is the acceler v; ,v(jobm; d(hb9qqe(f+m mcation of the less massive box?

Two boxes are connected by a cord running over a pulley as shown e/p gp8)wq*ol0/oaupin Fig. 4-5. Box I of mas0q//po a) 8wlop *ugeps
8.0 kg rest on the top of the table; the coefficient of kinetic friction between box I and the table is 0.10. Box II has a mass of 15.0 kg.
(a) Draw the free-body diagrams for the two boxes, identifying all of the forces acting on each of the masses.
(b) Calculate the acceleration of the system.
(c) Calculate the tension in the cord.

  The coefficient of sta4kpuaad 9ofm*t4z-7hda7qj7 tic and kinetic frictions between a 3.0-kg box and a desk pakdaj4 m9oh747u-zfq7d a* t are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions f,tr2jts6gqa 8 or plastic on wood are 0.50 andttqg68j a2 sr, 0.40,
respectively. How much horizontal force would you need to apply to a 3.0 N plastic calculator to start it moving from rest?

  An object slides on a level surface23pf:eq2 xmu9x8rssqhv89zb in the +x direction. It slows and comes to asf822r:p3qhx bsuqezv9m 9x 8 stop with a constant acceleration of -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a hodj c3(k *1bfy0pu7vbd rizontal surface is pulled by a 5.0-N force. A 3.0-N friction force ret3p 1*f yb0dkvd7jbu c(ards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, fn lwb ;b6 ;-f)wvcrtv(rom rest, at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initialhq 6d)v0o5r2qbevu628n ora m speed of 10 m/s. It slides 50 m on the ice before quroh2 ebo0a6dnvv 5 m8)6r2 qit stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation off k/7 -mm)iolvcq7f tn3z:sc, a traffic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were appf t7 )om7/l:3q,cfczn smkv-ilied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-(z u a psl4nd m1qp**k0jb:+nmv+e/ct6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes b 0eqv++s1zpn*/kmd4lamt*nu c: jp( is rough. If the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stambk eke2m 9wox5 9f)+bcked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the coefficient of static friction between +bew2b)m9x9km kf eo 5the boxes?

  An object is on a frictionless inclined plano4g fx1xf 1q:he. The plane is inclined at an angle o xhq:o411g ffxf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flaf(0xz9 i0p pqywrd) l3.pirf f ;r2(.lls-ciyt hill that makes an angle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth inclined 9.ml kdq j4hj 5eo25uvplane with an angle of $37^{\circ}$ to the horizontal. If the inclined plane is 5.0-m long, how long does it take for the mass to reach the bottom of the inclined plane after it is released from rest?

A block lies on a smooth inclin7 5 7+n6pe mdzeutd1ul3mb:gqed plane tilted at an angle of $35^{\circ}$ to the horizontal.
(a) Draw the free-body diagram for the block.
(b) Determine the block's acceleration as it slides down the inclined plane.
(c) If the block started from rest 8.5 m up the incline from its base, determine the block's speed when it reaches the bottom of the incline.
(d) How long did it take the block to reach the bottom of the inclined plane?

  A wooden block slides directly (bf5 fnm/bj 4zl,-2 jldzaw u.down an inclined plane, at a constant velocity ofz w,bb j5lm4-u/ .zdf2flnaj ( 6.0 m/s.
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a mass m slidekw9aj 7 d2/hojs down a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slides down vbtbr g4/9aw-a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. If the plane is 10 m long and the mass starts from rest, what will be its speed at the bottom of the plane?

  A bulldozer drags a log weighind 5wwp,f afz)(g 500 N along a rough surface. The cable attachewffz,)wa d p(5d to the log makes an angle of $30.0^{\circ}$ with the ground. The coefficient of static friction between the log and the ground is 0.500. What minimum tension is required in the cable in order for the log to begin to move?

A 25.0-kg box is released from rest on a roug;.yy db8vat-x h inclined plane tilted at an angle oy 8dyvx.;-tabf $33.5^{\circ}$ to the horizontal. The coefficient of kinetic friction between the box and the inclined plane is 0.200.
(a) Draw the free-body diagram for the box.
(b) Determine the force of kinetic friction acting on the box.
(c) Determine the acceleration of the box as it slides down the inclined plane.

  An object is placed on an inclined pr;wt92.0 tak oxz3aed lane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What iw9taz edx .0t2aro;3k s the coefficient of static friction between the object and the plane?